As far as I can tell, Biden didn’t control Congress. Senator Manchin, for example, effectively watered down the Build Back Better Act that Biden advocated for — and, to my knowledge, Biden never threatened him or any other Democratic members of Congress who resisted his legislative plans with “political consequences”, as Trump is doing to Republican House representatives in this instance.
In establishing himself as the Republican presidential candidate for the 2024 election, Trump seems to me to have set up a sort of cult of personality within the party such that Republicans either fall in line or out of favor.
I would characterize Tesla stock not as a pump & dump scheme anymore, but as a bet on Musk’s position to extract concessions from his political connections. He has got his way already with Trump planning to end EV subsidies that mostly benefited Tesla’s competitors, although Trump intended to do so anyway, and he may yet push against regulation that would threaten Tesla’s market position in the US, like federal charging standards. He may also get Trump to impose harsher tariffs on Chinese electrical vehicles than he otherwise would, although such tariffs enjoy bipartisan support.